Design Fraud Detection

Frame the Problem: The Opponent in the Loop

"Design fraud detection for a payments platform."

This question does not use the funnel at all. There is no catalog to narrow down. There is just a stream of transactions.

Each one needs a decision in tens of milliseconds, while the payment is held, waiting for your answer.

An important requirement here is handling adversaries: people who deliberately try to avoid detection.

Fraudsters can adapt to detection rules. Some patterns remain useful, while others change quickly